The present invention relates to a gas flow absorber, therethrough gas flows, in particular gas mixture flows are conveyed.
Absorbers operating based on the Pressure Swing Adsorption (P.S.A.) system are already known in the prior art, in which is also known that a fluidization of the inner bed of prior absorbers must be absolutely always prevented, by properly controlling the maximum rate of the fluid conveyed through the absorber device bed.
Said prior absorbers, conventionally comprises further diffusers arranged at the bottom and top of the absorber vessel, for allowing the absorber inlet fluid, such as oxygen or nitrogen or air mixtures, to expand in the absorber. To that end, prior absorber vessels have a diameter larger than the cross section of the gas inlet or outlet tubes. Thus, as a gas or fluid enters the absorber vessel, the rate with which said gas or fluid passes through the absorber material, usually comprising carbon or zeolites molecular sieves, decreases.
The above mentioned diffusers are usually made of thin metal perforated plates, in combination with metal layers having a different mesh size.
In particular, the mesh size substantially depends on the size of the bodies or particles used as an absorption material.
A further fluid diffusion system provides to use catalytic devices arranged within the absorber bed.
Such prior system, however, has the drawback that the gas flow fluid through the absorber is rather uneven, and, moreover, requires a comparatively long time for passing through the absorber vessel, thereby dead spaces are undesirably formed in the absorber vessel.
Moreover, the last approach has the drawback that the absorber volume has a comparatively large absorber volume dead part, for providing a required space at the gas or fluid inlet on the bottom of the absorber, as well as at the absorber top, where the outlet ports are formed.
In addition, said diffusion plates require to use a metal perforated disc to be arranged between the absorber outlet and inlet tubes, to prevent the fluid passing through the central portion of the diffuser from achieving excessively high diffusion rates.
Thus, the required additional dead space greatly increases the air or other gas contents in the stream or flow to be processed.
Furthermore, the making cost, weight and geometrical volume of the mentioned prior absorbers are also greatly increased.
In absorbers processing non dangerous fluids, such as air, hydrogen or the like mixtures, it is also known to use the so-called “cocomat” discs, or balls made of a ceramics or the like material, which balls are arranged between the diffusers and absorption material, to reduce to a minimum the dead space and further optimize the fluid flow diffusion within the absorber vessel.
In this connection, it should be pointed out that the above mentioned methods have the further drawback that they are not compatible with all the types of fluid passing through the absorption material, for example oxygen.
Moreover, they are not suitable to carry out very sophisticated procedures, requiring a very high refining degree.
Yet another drawback of prior plate diffusers is that the fluid flow passes through the absorption material bed in an uneven manner and, moreover, the absorption material and diffuser costs are very high.